The Neuromuscular System

Have you heard about the neuromuscular system? This system includes all the muscles in the body and all the nerves that connect them. All of our body movements require communication between our brain and the muscles. The nervous system bridges this gap and links thoughts and actions by sending messages, or electrical impulses, from the brain to the body. Nerves and muscles work together in this system to make the body move and manage vital functions like breathing.

Muscles are responsible for mobility, stability, posture, circulation, respiration, digestion, urination, childbirth, vision, organ protection, and temperature regulation. They make up about 40% of total body weight. There are about 600 muscles in the human body. 

Nerves are responsible for sending electrical signals to the brain to communicate sensations and to move muscles. They control important body functions such as digesting food and maintaining heart rate. There are about 7 trillion nerves in the body. The nervous system is the body's communication network that works together with the endocrine systems to control various functions. A nerve is a bundle of fibers that receives and sends messages between the brain and the body. These messages are sent by chemical and electrical signals in cells, called neurons, that make up the nerves. 

Nerves of the Body 

A nerve is a bundle of axons or nerve fibers from many neurons that are wrapped in multiple layers of connective tissue that contain blood vessels. 

The nervous system is divided into two systems. The Central nervous system (CNS) is the body’s command center, made up of the brain and spinal cord. The second system is the Peripheral nervous system (PNS), which is made up of the nerves that branch off from the CNS and transmit signals. 

The PNS is broken up into two divisions. The sensory division transmits information from inside and outside the body to the CNS. For example, this can be feelings of pain, smell, or even things we see. The second division is the motor division, which receives signals from the CNS that cause an action to occur. For example, these can be voluntary, like moving your leg, or involuntary, like the muscle contractions involved in digestion. 

There are 12 pairs of cranial nerves which are part of the PNS. These nerves originate from the brain and move outward to the neck, head, and face. These nerves can be sensory, motor, or both. Included is the olfactory nerve, which has sensory function and transmits information about smell to the brain. The oculomotor nerve is the motor function that controls the movement of the eyes. The facial nerve has sensory and motor functions that can transmit things like taste and movement of the face.  

The vagus nerve is the longest cranial nerve. It is involved in many areas of the body, such as the throat, heart, and digestive tract. 

Spinal nerves are also part of the PNS and branch from the spinal cord. There are 31 pairs of these, and they are grouped by the area of the spine they are associated with. These nerves are also capable of both sensory and motor function. 

There are then several hundred peripheral nerves throughout the body. There are sensory nerves that communicate about feelings on the skin, and nerves connected to the internal organs that all merge together, creating the sensory branches of the cranial and spinal nerves. One nerve may divide into 2 to 30 other peripheral nerves!